Carbon Capture Projects Turn CO₂ and Waste into Low‑Carbon Aggregates and Green Hydrogen

A commercial‑scale plant at the Port of Bilbao in northern Spain, part of the AGGREGACO2 project, is converting captured carbon dioxide and thermal residues from waste‑to‑energy facilities into low‑carbon construction aggregates. The facility, operated by Biscay Eco Aggregates—a joint venture that includes O. C. O Technology, Petronor and other Repsol‑affiliated partners—aims to capture up to 7,500 tonnes of CO₂ per year and produce as many as 125,000 tonnes of aggregates, replacing sand, gravel and crushed stone while permanently storing carbon. The project received €3.17 million from the EU Innovation Fund.

Separately, researchers at The Ohio State University led by post‑doctoral scholar Tomaz Neves‑Garcia have demonstrated a process that uses industrial by‑products such as steel slag and coal ash to capture CO₂ and convert it into high‑purity calcite and green hydrogen. The method reduces the energy required for water electrolysis, enabling hydrogen production with negative emissions. Their findings were published in ACS Energy Letters on July 8.